Kelly Clarkson reunites with original American Idol judges Simon Cowell, Randy Jackson and Paula Abdul

"I actually genuinely do not believe we would be sitting here today if you hadn't entered the show that year," Cowell said on Wednesday's The Kelly Clarkson Show. "The whole premise of the show was we had to find a star who was gonna sell records. We found some great people that whole year but when you delivered that moment on that first live show, when you sang that winning song at the end." Abdul added: "It was a game-changer."